Stud driver



Feb. 5, 1946. LA HUSB N 2,394,386

' STUD DRIVER Filed Jan. 15, 1944 4 Sheets-Sheet 1 3nventor 33 i7 M attorneys Feb. 5, 1946. 1.. A. HUSBAND 2,394,386

STUD DRIVER Filed Jan. 1:, 1944 4 Sheets-Sheet 2 5' Wi I 1: If

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H Smaentor Feb. 5, 1946. I L. A. HUSBAND 2,394,386

STUD DRIVER Filed Jan. 13, 1944 4 Sheets-Sheet 5 4 Snnentor attorneys L. A. HUSBAND STUD DRIVER Feb. 5; 1946.

Filed Jail. 15, 1944 4 Sheets-Sheet 4.

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Snnentor @712? (Q fivfiazrd v attorney Patented Feb. 5, 1946 STUD DRIVER Linton A. 'Husband, Elmhurst, Ill., assignor to General Motors Corporation, Detroit, -Mich., a corporation of Delaware Application January 13, 1944, Serial No. 518,069

11 Claims.

This invention is the outcome of efforts to develop a stud driving machine to speed up production, to get better results than can be had by hand operation with a sta dard torque wrench and to avoid physical fatigue and injuries to the operators.

The objects of the invention are, therefore, to save time in driving studs, to accurately determine the depth of driving, to cause the machine to cease operating if the stud being driven is oversize or undersize, and in other ways to solve the problems associated with driving studs and tightening bolts, screws and nuts.

On the accompanying drawings:

Fig. l is a view in elevation of the machine.

Fig. 2 is a similar view on a larger scale of a part of the machine. I I

Fig. 3 is a view as seen from line 33 of Fig. 1.

Fig. 4 is a horizontal section substantially on line 44 of Fig. 2.

Fig. 5 is a section on line 5-5-of Fig. 3. v

Fig. 6 is a section on line G6 of Fig. 3. Y Referring byreference characters to the drawings, numeral ll identifies the base of the machine from-which rises'a pedestal l3. A table to support the work W is marked [5. It is arranged to be adjusted vertically "by any convenient means, the drawings showing adjusting and holding operatingmembers at I! and I9. Projecting upwardly from pedestal; l3- is-a post 2lcarrying at its upper end a housing;23. The housing is mounted to rotate on-the post; 2| being limited in itsmovement by a shouldered collar 25. Slidable horizontally within housing '23 is an arm 21. A suitably mounted stop29 will serve to limit the movement of the arm in one directiornto the right as shown. 'Within the-housing 23 antifric tion rollers '24 maybe used-to guidethe arm.

A guide bar or way 3| issecured to the end ofarm zl for-;verticallyguiding a mounting bracket 33. An air pressure operated motor 35 is mounted on the arms of thebracket 33 for rotation on a vertical axis, anti-friction bearings being shown onFig; 2at'3'l; a

To move the bracket 33 with'the tically'on its guideway there is shown a lever 39. It is pivoted to the bracket at 4| and a link 43 connects its work end to arm 21. Downward pressure on the lever 39 moves the motor toward the work W" on the table. It. does so acting against 'a spring 45 housed within a tube 41. Tube 41 issecuredto-th e 'guideway 3| at 49. Within the tube and surroundedibythe-spring 45 1 i a post 5 l secured;- at -its;lo wer end-to the bracket 33. At'theupper'endof the postis a washer and nut assembly 53. As the bracket 33 moves downward the spring is compressed by the washer, the lower end of the spring being held by the cap 55 secured to the lower end of the tube 41. On Figs. 1 and 2 is shown at.51 what may be considered to be a stud driver of known construction and which is attached to and adapted to be rotated by the rotor of the motor. In this way the motor threads the stud down into the threaded opening of the work. The stud driver 51 will be of that known type which has a collet to grip the stud when rotated in driving direction and to release the stud when reversely rotated.

The operation of the-machine is automatic in that it drives the stud to a predetermined depth, whereupon the motor reverses and the stud is left in the work as sprin 45 raises the carrier 33 with the motor to its upper'limit. It is also automaticin that it accommodates itself to the fit of the threads of the stud in the work.v If the stud threads fit properly the engagement of the stud and work threads pulls the carrier 33 to its lower limit whereupon the motor rotation is reversed and the spring 45 pulls the motor and its carrier action produced upon the motor casing in'response to the varying resistance offered by the work being performed by the rotor. The torque I beam is shown on the drawings at 59. It is secured to and extends from the carrier 33 and therefore reciprocates with the carrier and the motor ver- 4 motor. An arm BI is secured to and projects from the motor casing in parallelism with the torque beam. Rotation of the motor on its vertical axis resulting from the torque load of driving the stud is transmitted from arm 6| to beam 59 by a connector marked 63. To vary the resistance to rotation oifered by the beam 59 provision is made as at for adjusting the connection and to lessen resistance there may be used rollers 61 on the connector for engaging the beam 59. Also any suitable bumper 69 may be used as a stop to enage the beam as it returns to its normal position after being bent therefrom by the rotation of the" motor casing. i

Thecontrolled rotation of the motor casing as described above is used in the following way to tric circuit by which a lamp bulb, not shown; is

small astud is being driven that there is no bending of the torque beam. In this case neither the normal, the excessive or the low torque switches ,come into operation. The motor merely travels illuminated to show the operator that the stud threading is meeting normal resistance, It will be readily seen that this normal resistance may be adjusted by moving theconnection 63 to a changed position on .bar GI. There may be'at tached to the motor casing a rod IGI (see Fig. 2)

extending through a slot I03 in a plate I05. The end of the rod is shown by Fig. 3 as provided with an indicator I01. The motor may be turned with a torque vwrench until the indicator I0I' reaches the location desired for normal torque and the necessary adjustment then given the connector 63. r

If a particular stud being driven is oversize the resistance todriving will cause the motor casing reaction to bend the beam 59 beyond its predetermined normal. The excessive rotation of the motor casing with the bracket II causes a spring controlled plunger 11 to actuate another switch marked I9. This switch operates tostop the machine. It has been stated that the motor is of the'air' pressure operated type. The switch may therefore function in any convenient way to close a valve, not shown, in the pressure line to the motor. After the defectiv stud ha been removed the machine may be againput in operation by a reset button such as I00. On the other hand the fit of the stud may be such that there is some motor casing rotation but less than normal, a condition corresponding to a stud threaded into 7 the work but not with a suificiently tight fit to properly hold. Again the machine is to be stopped automatically. The following provision is made "for this purpose. As shown in Fig. 2 a tubular post 8| is secured to the motor housing and is rotatably supported in the upper bearing of the bracket 33. To this post is secured by adjustable clampingmeans 82 an arm 83 having an extrusion '85 (Fig. 5).

adjusta'bly secured a clamp 81. ries a switch 88.

Clamp 8'! car Switch, 88 is positioned vertijcally somewhat below the uppermost position of arm 83'. It is designed to be actuated by extension 85 as the motor case reciprocates but only if there is a reaction rotation of the motor casing which is less than enough to actuate the switch 15 indicating normal torque. There is shown on Fig. 5 a roller 90 to be engaged by the extension 85. Fig. 5 shows the relative positions of mem bers 85 and 90 when there is no torque. case of normal torque when the arm 83 starts On spring housing 47' which extends in parallel relation to post 8I is In the downwardly it at once rotates to an extent sum cient to carry extension 85 beyond the vertical plane of roller 90. Then when the lower limit is reached and the motor starts to rise a no torque condition prevails and the extension again assumes the position shown by Fig. 5 and no con:

tact occurs. If, however, the torque is less than normal the extension 85, as it descends; will engage the switch actuator and stop the machine inithe way in which it was stopped by switch I9. The defective stud is removed and the mechanism is again reset. It may happen that so down carrying the stud, reverses and, since there has been no driving. torque, the, stud comes up with the driver until the upper limit is reached. The defective stud is thenremovedil.

In anyofthea'bovecases the acticn is to be stopped at the upper limit. To that end there is an' upper limit switch marked 91 carried by the guicleway. It is adapted to be engaged by anactuator marked 98 carried by the bracket. This switchcloses the how of air pressureand the action of the machine ceases.

. There will next be describedthe mechanism for automatically reversing the direction ofrotation of the rotor of the motor when the motor reaches 7 the lower limit of its travel. A solenoid controlled valve of well-known form is mounted on the base. direct the flow of compressedair through one or the other of two pipes 95 or 95 to a special valve marked I I9 which is attached to and controls the motor 35. 'When the motor carrier 33 descends to its lower limit an abutment 93 thereon operates a switch 9| to close a circuit through the solenoid controlled valve member '89. This functions to reverse the direction ofrotation of the rotor of the-motor. The airflow from pipe 95jenters the valve atfI09. From pipe 95' it enters the valve at 'I I I. Between points I09 and III thevalve II9 has a passage marked H3 in which reciprocates a valve rod I23. The rod I23 is operably connected by an arm I21 to a'rockshaft I25 sothat the shaft rocks in response to the. shift from pressure coming from pipe 95- to'pressure coming from pipe 95 and vice versa It may .be said that the air pressure motor withreveiising means controlled by the equivalent of-shaft I25 is not per se a part of this invention. The shaft I25 7 is flatted as shown at I26 in Fig. Band as it turns it causes air underpressure in space I29 to engage on opposite sides ofthe rotor, not shown-, to de-' termine the direction of rotation. The-air is admitted to space I29 byway of a passage I2I in theivalve, thepassage I2I communicating with the two openings I09 and III by passages II! and I20. In each .of the twopositions of the valve 1'0d:|23 it closes one of the passages I I'I or I20 asthe case maybe, air under pressure passing through the other passage' Not only is reversal effected by. the'lower limit switch but also it is caused by a switch operated by a button I22 7 at the end of the lever 39. It will be seen therefore that after reversal by the lower limit switch the motor is pulled up to its upper limit by spring 45,-where action ceases. For the next stud the operator pulls down on the lever and the still prevailing non-driving relation make possible the proper assembly of the collet of the driver with the stud. The button I22 is then manipulated and the resulting driving rotation then causesthe collet to grip the stud and the'engagement ofthe stud in the work pulls downthe motor until the rotation is again reversed by the lower limit switch and the-spring then pulls the motor to upper limit whereupon the action again stops.

It may be stated that applicant uses a standard air pressure motor, solenoid reversing valve and switches and makes no claim per se for these in strumentalities which he uses on his machine nor for the electrical equipment by which the parts are made to operate. The reversing operation of the air. pressure motor is not performed by hand It is marked 89. .It is designed to but by airpressureforfwhichhe ha'sdesignedthe special valve'markedHB. I L. 1 1

It will beseen that the machine candrive the studs to an accurately determined extent,-and that it requires only a slight manual effort to withdraw the motor carrier from the upper limit switch, engage the stud and. press the button to get forward driving rotation. The rest isautomatic. The threaded engagement is such as to pull the motor down against the resistance of. spring 45 until the solenoid reversing switch reverses the motor whereupon the collet releases its hold on the stud and the spring pulls the motor and carrier to its upper limit wherethe upper limit switch stops the operation. If any stud is defective the machine stops permitting its removal. r V l I claim:

1. In a stud driving machine, a motor, acarrier for said motor mounted to reciprocate, said motor having a reversible rotor, a stud driver carried by said rotor, said motor having a casing rotatably supported in said carrier, said casing rotating in response to the resistance offered by the work of driving a stud into the work, yielding means to resist said casing rotation and switches actuated by said casing rotation and operable to stop the rotation of the rotor in response to degrees of casing rotation corresponding to excessive or too little stud driving torque, first switch means to stop rotation of said rotor in response to a movement of the carrier to a predetermined upper limit and second switch means to reverse its rotation in response to the movement of the carrier to a predetermined lower limit.

2. The invention defined by claim 1, together with lever means to reciprocate said carrier and switch means on said lever means to reverse the rotation of said rotor.

3. Theinvention defined by claim 1, said motor being of the fluid pressure operated type, a solenoid flow changing valve, said second switch means operable in response to the movement of the carrier to its lower limit to actuate said flow changing valve to cause fluid pressure to take one or the other of two paths and reverse the rotation of the motor.

4. The invention defined by claim 1, said motor being of the fluid pressure type, a motor reversing valve secured to said motor, said valve having a reciprocable valve rod, a rockshaft to reverse the action of the motor, a link connecting said valve rod and rockshaft, and plural connections for fluid to move said valve rod in opposite directions, and said second switch means operable to transmit fluid pressure to said connections selectively.

5. In a stud driving machine, a motor carrier mounted to reciprocate between upper and lower limits, a reversible motor carried by said carrier, a stud driver carried by the rotor of said motor, means to stop rotor rotation in response to the movement of the carrier movement to its upper limit, means to reverse its rotation in response to movement of the carrier to its lower limit, together with means to stop the machine in response to excessive or too little resistance offered by the work.

6. In a stud driving machine, a motor carrier mounted to reciprocate between upper and lower limits, a reversible motor carried b said carrier, a stud driver carried by the rotor of said motor, means to stop rotor rotation in response to the movement of the carrier movement to its upper limit, means to reverse its rotation in response tomovement'of the carrier :to its lower. limit, said motorthavingza casing journaled. for rotation on a vertical axis, torque responsive means toresist the rotation of said :casing, together with means to stop the machine in response to excessive torque and also in responseto a degree of torque less than a predetermined minimum.

-7. Ina stud driving machine,a motor carrier mounted to reciprocate between upper and lower limits, a reversible motor carried by said carrier, a stud .driver carried by. the rotor of said motor, means to stop rotor rotation in response to the movement of the carrier movement to its upper limit, meansto reverse its rotation in response to movement of the carrier to its lower limit, said motor having a casing journaled forrotation on a vertical axis, torque responsive means to resist therrotation of said casing, together with means to stop the machine in response to predetermined degree of torque, said torque responsive means being a flexible torque beam secured to said carrier; a rigid rod parallel thereto attached to the motor casing and connecting means therebetween.

8. In a stud driving machine, a motor carrier mounted'to reciprocate between upper and lower limits; a reversible motor carried by said carrier, a stud driver carried by the rotor of said motor, means to stop rotor rotation in response to the movement of the carrier movement to its upper limit, means to reverse its rotation in response to movement of the carrier to its lower limit, said motor having a casing journaled for rotation on a vertical axis, torque responsive means to resist the rotation of said casing, together with means to stop the machine in response to predetermined degrees of torque, said torque responsive means being a resilient beam secured to and extending from said carrier, a rigid rod parallel to said beam and secured to said casing, connecting means therebetween, and a plurality of switch contacting means rotatable with said motor casing and adapted to engage and close motor stopping switches in positions of the casing corresponding to excessive bending of said beam and to a bending which is so small as to indicate too little resistance in the work.

9. In a stud driving machine, a motor carrier mounted to reciprocate between upper and lower limits, a reversible motor carried by said carrier, a stud driver carried by the rotor of said motor, means to stop rotor rotation in response to the movement of the carrier movement to its upper limit, means to reverse its rotation in response to movement of the carrier to its lower limit, said motor having a casing journaled for rotation on a vertical axis, torque responsive means to resist the rotation of said casing, together with means to stop the machine in response to predetermined degrees of torque, said torque responsive means being a resilient beam secured to and extending from said carrier, a rigid rod parallel to said beam and secured to said casing, connecting means therebetween, and a plurality of switch contacting means rotatable with said motor casing and adapted to engage and close motor stopping switches in positions of the casing corresponding to excessive bending of said beam and to a bending which is so small as to indicate too little resistance in the work and an additional switch contacting means rotatable with said casing and operable in response to an intermediate bending of the beam to give indication that the resistance ofiered by the work is normal.

10. In a stud driving machine, a motor carrier mounted to reciprocate between upper and lower means to stop rotor rotation in response to the movement of the carrier movement to its upper limit, means to reverse its rotation in response to movement of the carrier to its lower limit,-

said motor having a casing journaled for rotation on a vertical axis, torque responsive means to resist the rotationof said casing, together with means to stop the machine in response to predetermined degrees of torque, said torque responsive means being a resilient beam secured to' and extending from said carrier, a rigid rod parallel,

to said beam and secured to said casing, connect-,-

- ing means therebetween, and a plurality of switch contacting means rotatable-with said motor casing and adapted to engage and close motor stopping switches in positions of the casing corresponding to excessive bendingof said beam and to a bending which is so small as to indicate too little resistance in the work, said switch which is operable in response to too little resistance being ,fiXedly mounted and the switch closing means therefor which rotates'with the motor casing being on opposite sides of the vertical plane of said switch in high torque and no torque positions and adapted to render the switch operable limits, a reversiblemotor carried by said carrier, 7 a stud driver carried by the rotor of said motor,

only in a position between the upper and lower positions of'the motor casing and in response to a low torque rotary positionof' said casing.

11. In a stud driving machine, a motor carrier mounted for reciprocation between upper and lower limits, said moto-rthaving a rotor to'perform work and a casing rotatable in, said carrier on a I vertical axis, yielding torque resisting means mounted on said carrier, means on the motor 'casiIlg to variably effect said yielding means in rethe carrier movement, means mounted on the carrier to actuate said switch to stop the machine, motor reversing means including a switch adjacent the lower limit of carrier travel, means on the carrier to actuate said switch, manual means to reciprocate said carrier and a second reversing switch operating means on said manual means,

LIN'IYON A. HUSBAND. 

